Many chromium compounds have been described in the literature.
Mono-and-binuclear chromium complexes are known in the art. E.g., tetrakis(trimethylsilylmethyl)chromium(IV), Cr(TMS).sub.4 ; bis(.mu.-trimethylsilylmethyl)-bis-[(trimethylphosphone)(trimethylsilylmet hyl)]dichromium(II), [Cr.sub.2 (CH.sub.2 SiMe.sub.3).sub.4 (PMe.sub.3).sub.2 ]; bis(.mu.-allyl)-bis(allyl)dichromium(II), Cr.sub.2 (C.sub.3 H.sub.5).sub.4 having been disclosed by their chemical name. The term "TMS" refers to the trimethylsilylmethyl ligand.
Chromium compounds have a wide variety of utilities depending upon their structure and their specific activities. Certain inorganic hexavalent chromium compounds, in particular, CrO.sub.3, have been found to be highly active catalyst components in the catalytic polymerization of ethylene and other olefins. This fundamental discovery has led to significant research and further chromium compounds have been discovered which are useful in the general area of olefin polymerization. It is a continued goal to find new chromium compounds having specific properties rendering them useful for particular applications.